"I'm quite passionate about this," Mr Younger, who is known as C, told the Guardian. "We have to go out and ask these people to join us. Before we were avowed as a service, that was the only way of recruiting people, a tap on the shoulder.

"That was the way I was recruited. We have to go to people that would not have thought of being recruited to MI6. We have to make a conscious effort. We need to reflect the society we live in.

"Simply, we have to attract the best of modern Britain. Every community from every part of Britain should feel they have what it takes, no matter what their background or status. We have to stop people selecting themselves out."

He added: "We have suffered from groupthink in the past. We have to get the maximum [number of] differentiated points of view in the room and for people to have the confidence to say what they think. Even if it's not the popular thing to say, even with people like me."

MI6 is expected to grow from 2,500 people to close to 3,500 by 2020.

An unnamed recruitment boss said the legacy of the world's most famous fictional spy meant some applicants believed being a good shot was an advantage. The macho image also deters some people from putting themselves forward.

She told newspaper: "They may well be able to use a revolver. But that is not really what we are looking for. We don't want to be the SAS. The brand has attracted a lot of good people. But it has also put off equally fantastic people.

"There is a perception out there that we want Daniel Craig, or Daniel Craig on steroids. He would not get into MI6. We need to get that message across because it is so embedded, and we have to get around that. We are between a rock and a hard place - between trying to be innovative, while protecting the secret stuff that keeps this country safe.

"We get thousands of people applying. But we need people from a wider range of backgrounds in order to be able to select the best talent this country has to offer."